Electrochemical Analysis of Austenitic Stainless Steel (Type 904) Corrosion Using Egg Shell Powder in Sulphuric Acid Solution

摘要

Stainless steel is one of the most widely used metals in many industries resulting from the formation of protective film layer on their surface which prevents the metal to react with corrosive environments such as, sulphuric acid. This acid contains various impurities, including aggressive agents which increase the risk of corrosion damage depending on the type of stainless steel used. In addition, it has been shown that corrosion causes acceleration in electrochemical process leading to decrease in the resistance of materials. This research objective is to investigate egg shell powder as corrosion inhibitor on (Type 904) stainless steel in 0.5M H2SO4 environment. This research utilized weight loss and potentiodynamic polarization measurements. Egg shell powder was found adequate to reduce corrosion rate of stainless steel Type 904 by 99.45% efficiency. The optimum concentration of inhibitor was 8g/250 ml 0.5% H2SO4. From polarization study, egg shell powder was indicated as mixed type inhibitor with predominant cathodic effect. In addition, the egg shell powder completely adsorbed onto the stainless steel surface following Langmuir isotherm.